The main products of the fragrance industry have always been concentrated essences in the form of clear alcoholic liquids, commonly known as perfumes, colognes, and toilet waters. From time to time, however, the industry has introduced emulsified and solid forms of fragrance.
The main problem in formulating emulsified fragrances is that of producing a stable emulsion. This is rendered difficult by the high concentration of perfume oil used. The product must not be greasy upon application to the skin and must not leave an oily residue.
Among the commonly used emulsifying agents are the following:
Carboxy vinyl polymers neutralized with alkalis PA1 Fatty acid soaps PA1 Sulfated alcohols PA1 Oleyl ether phosphates PA1 Polyhdric alcohol esters PA1 Polyethylene oxide ethers PA1 Polyethoxylated sorbitan esters PA1 Sorbitan esters PA1 Liquid solutions of lanolin alcohols PA1 Polyethylene glycol esters PA1 Acetylated polyoxyethylene derivatives of lanolin PA1 Nonylphenoxypoly ethyl alcohols PA1 Polyethylene glycol ethers of lanolin alcohol PA1 Ethylene oxide condensate of a propylene oxidepropylene glycol condensate PA1 Ethoxylated cholesterol PA1 hydroxypropyl cellulose acetate PA1 hydroxypropyl starch acetate PA1 hydroxypropyl cellulose laurate PA1 hydroxypropyl starch laurate
Combinations of the carboxy vinyl polymer emulsifying agents (e.g. Carbopol 934,940 and 941) are the most versatile and generally yield satisfactory emulsified fragrances. One problem with carboxy vinyl polymer agents is unwanted microbial growth. The use of antimicrobials is called for to prevent mold growth. Depolymerization by ultraviolet light is also a troublesome problem. The use of ultraviolet light absorbers can minimize this problem.
The high concentration of perfume oil used in emulsified fragrances results in unstable emulsions. The higher the concentration of perfume oil, the more difficult is the stabilization of the emulsion.
Viscosity stabilization is another problem frequently encountered in emulsified fragrances. Some formulations become too viscous to flow through the opening of the bottle; others decrease in viscosity to a watery consistency.
Solid colognes are essentially liquid colognes which have been solidified with a gellant, and are usually composed of the following materials:
______________________________________ Perfume 2 - 5% Ethyl Alcohol 85 - 90% Solidifying Ingredient 6 - 5% Polyhydric Alcohol 0 - 5% Water 5 - 10% ______________________________________
Hard soaps are used as the solidifying agent. One soap generally used is sodium stearate. The presence of unsaponifiable matter and oleates tends to interfere with gelation. Other solidifying ingredients include rosin soaps, candelilla wax, beeswax, carnauba wax, potassium diacetone fructose sulfate, acetanilide, calcium acetate, and ethyl cellulose.
The inclusion of potassium chloride, castor oil, or castor oil fatty acids is desired for the preparation of clear, transparent gels, but castor oil and its fatty acids tend to reduce the gel strength.
It is an object of this invention to produce a gelled perfume with pleasing clarity and enduring fragrance. It is a further object to produce a gelled perfume that avoids unwanted microbial growth. It is still a further object to produce a gelled perfume that is highly stable and that also has a stable viscosity.